A variety of technological systems exist for determining the position geographic objects. For example, cell phones often include GPS receivers and accelerometers to determine their own geographic position and orientation.
Devices also exist for determining the geographic position of other objects. A total station is an optical instrument used in surveying to take measurements of scenes. It is a combination of an electronic theodolite (transit), an electronic distance meter (EDM) and software running on an external computer known as a data collector.
With a total station one may determine angles and distances from the instrument to points to be surveyed. With the aid of trigonometry and triangulation, the angles and distances may be used to calculate the coordinates of actual positions (X, Y, and Z or northing, easting and elevation) of surveyed points, or the position of the instrument from known points, in absolute terms.
The data may be downloaded from the theodolite to an external computer and application software will generate a map of the surveyed area.